The use of dynamic radio frequency identification (RFID) scanning tunnel technology allows for high speed bulk reading of the RFID tags belonging to large numbers of objects. Often, such RFID tags are affixed to or integrated into cartons that are used in a manufacturing supply chain, such that the RFID tags can be read by the scanning technology at various touch points throughout the supply chain. Dynamic scanning allows for a much greater efficiency than many other solutions, and offers the capability to process much higher volumes of carton-packed items than many other solutions.
However, one challenge with high speed scanning that must be addressed is how to deal with cartons or other items that are read by the high speed scanning tunnel and which are flagged by the high speed tunnel as exceptions. An “exception” typically means that the carton failed in some manner; for example, a carton might be flagged as an “exception” based on the carton being short on its total expected count of items, or having improper items. Typically, when a carton is flagged as an exception, the carton must be opened up, and each item within the carton must be evaluated to ensure that the carton was properly prepared. This means that, typically, the audit area of a manufacturing facility will include multiple stations that must be constantly attended by auditors equipped to conduct audits of these cartons. Often, it will also mean that items must themselves have individual RFID tags such that the items within a carton can be audited within a reasonable timeframe.
Traditionally, conducting any kind of RFID audit processes in the retail supply chain environment has been extremely challenging. The challenges to conducting a proper audit exist on several levels.
First, in a distribution center environment, there is the potential to have a very high inventory of product, some or all of which may be tagged with RFID transponders at the item level. These large populations of RFID tags can be excited by any nearby RFID reader device emitting an RF field, which may cause inadvertent reading of tags that were not intended to be read during an audit process. For example, in some cases, even the RFID tags of items in other cartons that are moving past an RF field can be energized, causing false reads.
Second, the methods that may be used to read tags during an audit may pose unforeseen hurdles. This may be because of, for example, the infrequency of use of the RFID scanning technology that is used to conduct the audit, which may result in errors owing to workers' unfamiliarity with the devices, or may result in poorly-calibrated scanners escaping detection for some time. The RFID scanning devices used for the audits may also be less sophisticated than RFID devices incorporated into a supply chain or production line, which may result in problems arising from the use of these “lesser designs.” This may require, or may motivate, the customer or other operator of these RFID devices to take drastic measures in an attempt to correct the issues.
A typical RFID audit process requires the ability to perform a singulation of an RFID tag or tags. This means that, in a typical audit solution, it is incumbent for the RFID scanning device to have a read field that is only just large enough to interrogate a very small population of tags. This may be, for example, only around 1 to 10 tags, or may be a higher number of tags depending on the process in question. It is also extremely important that the RFID device have a very well-defined target field in which it can read tags. For example, in one case, the target field for an RFID scanning device may only be 12 inches square and emanate roughly 2 inches above the scanning surface.
Such audit processes may often make use of handheld RFID scanning devices. While certain advantages of using handheld devices do exist—for example, a person conducting an audit may be able to narrowly define a target field of the desired size by utilizing a very low-ranged handheld device and moving it throughout the target field—this has generally met with limited success. Likewise, in some cases, audit processes have made use of segregating tags to be scanned into a tightly controlled environment where there is no possibility that errant tags can be read; however, this is often much less convenient than the alternative, and can be disruptive to the supply chain or manufacturing process.